Floating point operations per …?
FLOPS = FLoating point Operations Per Second, akin to the power of a given machine (which could be measured in Watt = Joule per second)
A task of W FLOP on a machine capable of P FLOPS will take T=W/P seconds. Or, a machine capable of executing a task of W FLOP in T seconds is capable of P=W/T FLOPS.
TL;DR: 1 FLOPS = 1 FLOP/sec
The author of this post seems to have fallen for this error.